Converse (deterministic and stochastic) ecological process drive soil bacterial and fungal community assembly in subtropical forest

The mechanisms of soil microbial assembly have been well understood at global and regional scales. However, there is a lack of understanding in soil microbial, especially bacterial community assembly and its driving factors at local scales. This study aimed to explore the relationships between plant diversity, microbial diversity and soil properties at a local scale, starting from the two levels of biodiversity, phylogenetic diversity and species diversity. LEfSe analysis revealed significant enrichment differences in bacterial from genera to the phylum among three microhabitats, while fungi are only found to be enriched in certain species in a microhabitat. Significant differences in not only microbial species diversity and phylogenetic diversity but also community structures were found among the three habitats. Null model analysis was used to quantify the relative importance of deterministic and stochastic ecological process. The results shown that homogeneous selection prevailed in bacterial assembly and dispersal limitation dominated the fungal assembly. Although the microbial community structure was drove to converge at the local scale, the driving forces of community assembly of fungi and bacteria are different. Finally, the results of linear regression and structural equation modelling indicated that plant diversity had a greater effect on microbial species and phylogenetic diversity compared to soil properties. Our results emphasized the importance of plant diversity in shaping microbial community assembly and its diversity at local scale in subtropical forest soil.